• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.348-350
• /
• 2021

When predicting the concentration of fine dust using deep learning, there is a problem that the characteristics of a high concentration of 81㎍/m³ or more are not well reflected in the prediction model. In this paper, a comparison through predictive performance was conducted to confirm the results of reflecting the characteristics of fine dust in the high concentration area according to the deep learning algorithm. As a result of performance evaluation, overall, similar levels of results were shown, but the RNN model showed higher accuracy than other models at concentrations of "very bad" based on AQI. This confirmed that the RNN algorithm reflected the characteristics of the high concentration better than the DNN and LSTM algorithms.

• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.66.2-66.2
• /
• 2013

As part of the DIGIT key program, we observed GSS30-IRS1, a Class I object located in Ophiuchus (d=125 pc), with Herschel-PACS. More than 70 lines were detected in 50-200 micron band including CO, OH, H2O, and [OI]. All lines, except for [OI], were detected only at the central spaxel of $9.4^{{\prime}{\prime}}{\times}9.4^{{\prime}{\prime}}$ while the [OI] emission is extended along the NE-SW direction. One interesting feature in GSS30-IRS1 is that the continuum is extended beyond PSF, unlike line emission. It suggests that the external heating is important in GSS30-IRS1. For detail analysis of line fluxes, we apply the non-LTE LVG model, RADEX as well as simple rotational diagrams. We also use the Monte Carlo radiative transfer package, RADMC-3D to understand the heating mechanism of dust grains around GSS30-IRS1. We will discuss about heating and cooling processes associated with GSS30-IRS1.

• Journal of Astronomy and Space Sciences
• /
• v.12 no.1
• /
• pp.1-13
• /
• 1995

We carried out photometric and spectroscopic observatious of the blue compact dwarf galaxy Haro 6 in the Virgo Cluster of Galaxies. The long-slit spectroscopy was employed at three position angles, $\Phi$=$0^{\circ}$, $\Phi$=$30^{\circ}$, and $\Phi$=$120^{\circ}$with CCD camera mounted on the Cassegrain Spectrograph. Based on the mean intrinsic axial ratio < $q_0$ >=0.3, we derived inclination I of the system as $44^{\circ}$using our composite V-band CCD image. Careful analysis on the velocity field of the system shows an asymptotically fiat rotation curve with the maximum rotational velocity $V(r)_{max}$ reaches about 12km/sec. The calculation of the dynamical mass of Haro 6 with a simple mass model is briefly discussed with emphasis on the mass to luminosity ratio. From the IRAS Point Source Cataloque, we derived dust-to-gas ratio which indicates relatively low dust content, thus tempting us to conjecture the youth of the system.

• Journal of The Korean Astronomical Society
• /
• v.42 no.4
• /
• pp.81-91
• /
• 2009

We make a new catalog of AGB stars in our Galaxy from the sources listed in the Infrared Astronomical Satellite (IRAS) point source catalog (PSC) compiling the lists of previous works with verifying processes. We verify the class identification of AGB stars into oxygen-rich and carbon-rich stars using the information from recent investigations. For the large sample of AGB stars, we present infrared two-color diagrams from the observations at near infrared bands and IRAS PSC. On the two-color diagrams, we plot the tracks of theoretical radiative transfer model results with increasing dust shell optical depths. Comparing the observations with the theoretical tracks, we discuss the meaning of the infrared two-color diagrams.

• Journal of Power System Engineering
• /
• v.10 no.2
• /
• pp.16-21
• /
• 2006

On this study, numerical analysis was performed for the 3 dimensional flow field of gas and particle phase for axial inlet cyclone, a part of dust collector. We applied FVM to visualize the gas phase. The flow was solved using ${\kappa}-{\varepsilon}$ turbulence model. The major parameters considered in this study were helical guide vane, inner diameter, length. Particle trajectory calculations were performed for the particle sizes of $5{\mu}m{\sim}75{\mu}m$. The distribution curve of particle sizes was made of Rosin-Rammler function. The simulation results show various gas flows, particle trajectories on numerical models.

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.1
• /
• pp.60.1-60.1
• /
• 2014

The star ${\zeta}$ Ophiuchi (HD 149757) is one of the brightest massive stars in the northern hemisphere and was widely studied in various wavelength domains. We report the analysis results of far ultraviolet (FUV) observations with other wavelengths for around ${\zeta}$ Ophiuchi. We study the correlation of between multi wavelength observations. We have developed a Monte Carlo code that simulates dust scattering of light including multiple encounters. The code is applied to the present Oph HII region to obtain the geometrical information of dust such as distance and thickness. Also We apply three-dimensional photoionization code to model Wisconsin $H{\alpha}$ Mapper observations of the H II region surrounding the star.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2010.05a
• /
• pp.460-466
• /
• 2010

단일 알루미늄의 연소 모델을 사용하여 알루미늄 분말의 점화 과정에 대한 전산유체 해석 기법을 개발하였다. 유동의 계산은 Reynolds averaged Navier-Stokes식을 사용하였으며, $k-{\epsilon}$ 난류모델을 적용하였다. 입자는 Eulerian-Lagrangian 방법을 사용하여 유동과 독립적으로 계산을 수행하였으며 상용 전산유체해석 프로그램인 Fluent 6.3을 사용하여 해석을 수행하였다. 단일 모델에서 사용한 대류 및 복사 열전달, 표면이상반응, 알루미늄의 용융열을 입자 가열원으로 고려하였다. 같은 조건을 사용하여 단일 입자 모델 계산과 전산유체해석을 수행하였으며, 두 결과는 5% 이내로 잘 일치 하였다. 이를 통해 전산유체해석에서 알루미늄의 점화를 모사할 수 있음을 확인하였다.

• Publications of The Korean Astronomical Society
• /
• v.16 no.1
• /
• pp.7-10
• /
• 2001

In the framework of the C-gauge condition for the perturbed variables and the linear approximation for the anisotropy of the spacetime, we studied the formulae for the Sachs-Wolfe effect in dust filled and perturbed Bianchi type I universe model. The results were compared with those of the flat Friedmann model.

• The Bulletin of The Korean Astronomical Society
• /
• v.45 no.1
• /
• pp.42.2-42.2
• /
• 2020

We report on multi-wavelength observations of AA Ori, a Young Stellar Object in Orion-A star-forming region. AA Ori is known to have a pre-transitional disk based on infrared observations including Spitzer/IRS data. We construct its broadband spectral energy distribution (SED) by not only taking data in the optical and IR region but also including Herschel/PACS, JCMT/SCUBA, and SMA observational data. We use the Monte Carlo radiative transfer code (RADMC-3D) to reconstruct the SED with a viscous accretion disk model initialized by a radially continuous disk and finally having an inner and outer dusty disk separated by a dust-depleted radial gap. By comparing the model SEDs with different configurations of disk parameters, we discuss the limits to find a single solution of model parameters to fit the data. We suggest that some models with a modified inner disk surface density gradient and some degree of dust depletion in the inner disk can explain the AA Ori's SED, from which we infer that the inner disk of AA Ori has evolved. We present that model configurations of a pre-transitional disk with a large gap extended to 60-80 AU in a settled dusty disk of a few hundred AU size with a high inclination angle (~60°) also create model SEDs close to the observed one. To distinguish whether the disk has a just-opened narrow gap or a large gap, with an altered surface density of the inner disk extended to 10 AU, we suggest a further investigation of AA Ori with high angular resolution observations.

• The Journal of Information Systems
• /
• v.28 no.1
• /
• pp.133-153
• /
• 2019

Purpose The purpose of this study is to design a regional electricity planning model rather than the existing single region ones and verify its usefulness. The regional electricity planning model is to determine both electricity distribution among regions and power plant planning at the same time satisfying regional demands and distribution networks. Design/methodology/approach This study made a regional electricity planning model by integrating power plant planning and electricity distribution among regions. The regional electricity planning model is formulated into a linear programming problem, and coded and run using the OSeMOSYS, one of open source energy systems. Findings According to the empirical analysis result, this study confirmed that the regional electricity planning model proposed in this study deducts the unfairness among regions in view of electricity and green house gas. In addition, the model is expected to be used in evaluating and developing the national policies concerning fine dust and/or green house gas.